Aerodynamic behaviour of cables against skew wind

摘要

Dry inclined cable galloping and limited-amplitude high-speed vortex excitation have been observed recently on inclined cables under no precipitation conditions. These unfavorable motions potentially threaten the safety of structures, thus cause serious concerns in the design of cable-stayed bridges. To find effective field solutions, mechanisms of these unstable behaviours need to be clarified. A series of dynamic and static model wind tunnel tests have been carried out in the present study to investigate these phenomena. Results show that characteristics of dynamic responses and aerodynamic forces of these two types of motion are different. The former could be excited by a mechanism similar to that can be described by the Den Hartog criterion, whereas the latter might be generated by the coupling between vortex shedding in the wake and along the cable. The issues need to be further investigated are also discussed.